﻿#include <iostream>
#include <vector>

using namespace std;

class Solution
{
public:
    // 96. 不同的二叉搜索树
    int numTrees(int n)
    {
        vector<int> dp(n + 1);
        dp[0] = 1;

        for (int i = 1; i <= n; i++)
            for (int j = 1; j <= i; j++)
                dp[i] += dp[j - 1] * dp[i - j];
        return dp[n];
    }
};

int main()
{
    cout << Solution().numTrees(5) << endl;

    return 0;
}